I read in the mileage run forum that some people always keep two OWE tickets open, but they did not elaborate on the specific advantages of doing so. What are some of the significant advantages you can think of? Perhaps having one in each direction and using them like like a multiple-segment round trip ticket?

Also, if I start off my OWE in Mexico, would that allow me to get 5 other North America segments and unlimited stopover in US/Canada for the 5 NA segments? I read in another thread that Canada is considered the same COUNTRY as US for OWE purpose, not just the same continent.